"Traditional supply chains are linear. Materials are mined, manufactured as products, and often end up in landfills after use. Then the process starts over and more materials are extracted from the earth for new products. We believe our goal should be a closed-loop supply chain, where products are built using only renewable resources or recycled material," Apple report said.

"We're also challenging ourselves to one day end our reliance on mining altogether."

But the task won't be easy, something that Apple has admitted. The company's vice president of environment, policy and social initiatives told VICE news that Apple doesn't know how it will be achieved.

"We're actually doing something we rarely do, which is announce a goal before we've completely figured out how to do it," Lisa Jackson said.

Apple described some of the initiatives it has in place to hit its goal. It has a robot called Liam which is able to disassemble products and recover components that can be recycled. The company is also encouraging customers to return products through its Apple Renew recycling program.

The world's second-largest smartphone maker is also looking into ways to reuse materials. For example, it melted down the aluminum enclosures on the iPhone 6 to make Mac mini computers to use in its factories and it said that it is moving to 100 percent recycled tin solder on the main logic board of iPhone 6s.

It has focused on a different way of producing aluminum which has resulted in the iPhone 7 enclosure using 27 percent less of the material than the iPhone 6, and emitting 60 percent less greenhouse gas emissions.

Of course, Apple also relies heavily on many suppliers to provide components for its devices and this can often be where there are issues with so-called "conflict minerals" and environmentally-disastrous production techniques. But Apple said that seven major suppliers have now pledged to power their Apple production entirely with renewable energy by the end of next year.

Apple has been on a big push towards running a more environmentally sustainable business, something that the electronics industry has been criticized for from campaigners and analysts. A recent report by Verisk Maplecroft warned that "conflict minerals" – which refers to the production of tin, tantalum, tungsten and gold tainted by human rights abuses – are still getting into the tech supply chain.

Of course, Apple's pledge on renewables would not only be good for the environment, but also for its business.

"A totally recycled smartphone will help Apple to increase loyalty among eco-friendly consumers and eventually reduce their production costs by using some of the components from older phones," Francisco Jeronimo, research director for European mobile devices at IDC, told CNBC by email.

In 2016, 96 percent of the electricity used at Apple's global facilities came from renewable energy. It is 100 percent renewable in 24 countries and all of its data centers.